Examine source code of Tab Manager

{
  "manifest_version": 2,
  "name": "Tab Manager",
  "version": "1.0",
  "description": "An extension to manage and save tabs.",
  "icons": {
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "index.html",
    "default_title": "Tab Manager",
    "default_icon": {
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "applications": {
    "gecko": {
      "id": "dev@techguardianacademy.com",
      "strict_min_version": "78.0"
    }
  }
}